nonamp add-to-cart not working

Hi,

I placed add to cart link to nonamp page with nonamp=1 but i still not redirected to nonamp page. e.g : https://mydomain.com/achat-immediat/?nonamp=1&add-to-cart=204653
but i’m forwarded to https://mydomain.com/achat-immediat/amp/ only if visitor coming from https://mydomain.com/amp. if i come from https://mydomain.com i not have the mentioned issue.

Regards